Last April, Rob Campbell played a joke. On his blog, the Wieden+Kennedy Shanghai planning head wrote about 'Method Planning™'. This new research methodology was inspired by the notion of method acting, whereby actors literally spend 24/7 in character to more deeply assimilate the motives and psyche of the person they're playing. Rob wanted to explore whether this quest for authenticity would bear fruit for planners looking for more authentic consumer understanding.

"So much of what we 'learn' is second hand," he wrote. "So when we were recently given a project that required us to understand entry-level white collar employees, I couldn't help but take the opportunity to explore the method acting approach… which is why for the last five weeks, one of my planners has basically been living someone else's life."

Leon, a W+K planner, had been sent to Wuhan, a Chinese city, to assume a new undercover life as a clerk in a local bank. He'd had the perfect résumé dreamt up and a temp agency had landed him the job. He shared a flat with three unwitting housemates, eating the same food, living on the same low salary and experiencing the same highs and lows.

"When he tells us the challenges and experiences he's going through, he no longer talks about them in terms of observation, but personal feelings. In short, Leon is no longer observing our target audience, he is our target audience. I would say Method Planning™ offers ad agencies a whole new approach to gaining powerful and influential audience insights… though I would suggest the best time to do it is on April 1st because people are way more gullible on that day."

I completely fell for what Campaign Asia called Rob's 'very respectable April Fool's Day prank', but I felt more inspired than tricked. That we struggle to truly understand the people to whom we're marketing is a sound insight, and I thought he was on to something.

Two months later at the Young Planners Academy in Cannes, we heard from Spencer Baim, Vice Media's chief strategy officer. He talked to our class about Vice's mission 'to be the voice of their generation'. Their commitment extends well beyond the usual lip service, because they have a policy of only hiring Millennials – people of the same generation as their audience. The average age of their London office staff is 27, and those young journos are given the kind of editorial control that would inspire dizzying anxiety in their older (and often struggling) media contemporaries. And it works. The authenticity of their voice has resulted in Vice being more popular, more profitable and more valuable than The New York Times. And it's growing at a rate akin to Silicon Valley technology companies.

The success of Vice's speed and accuracy in engaging Gen Y underscores the hopelessness of Baby Boomer media company execs stumbling around under the dim light of Millennial research reports. Vice's methodology is less covert than Rob's. But they share an important belief, which is that you're most likely to understand an audience when you are that audience.

So where does that leave the rest of us? Puristically speaking, probably with a very finite sliver of available briefs for which we're both planner and consumer. But Method Planning, minus the logistical adversities of truly going undercover, might yet save us.

I heard a great story of a design company here in Auckland who did a job with the Italian furniture designer Natuzzi. They were called in to help Natuzzi's designers think more creatively. Feeling self-conscious about the plausibilty of their having much to teach Italians about furniture design, they instead created a cunning way of getting them to walk a mile in their customers' shoes. Or, as it turned out, sit a day in their customers' underpants. They created a range of underwear for Natuzzi's designers. On each pair, they printed a profile of somebody from one of Natuzzi's key customer segments. Who they were, what their lives were about, what they did in a normal day, how their behind was likely to be utilised. Each designer received a set, and was encouraged to choose a pair each morning and then to 'be' that person for the rest of the day – imagining where they might sit, how they might sit and what they might find lacking in the chairs beneath them.

We spend a lot more time observing consumers than trying to be them. While spending a day in somebody's underpants might lack the ambition of spending weeks as a bank clerk in Wuhan, the notion of 'being' the consumer feels like a compelling alternative to simply researching them.